1. Field of the Invention
The present invention relates generally to assemblies and systems for securing roofs to their underlying structures in order to avoid damage due to high winds. More particularly, the present invention comprises a series of tiedown straps which are secured to corresponding ground anchors on opposite sides of a building structure, and which pass over corresponding bearing plates placed upon the roof structure. The bearing plates each include one or more rollers extending upwardly therefrom, upon which the tiedown straps bear.
2. Description of the Related Art
Wind damage to building structures is a common result when high winds occur, particularly in the case of conventional frame structures having gabled roofs. The roofs of such structures generally depend upon their weight to achieve most of their security, and high winds can create enough lifting force to completely counteract the weight of the roof upon the structure. When this occurs, the roof, or portions thereof, are often blown away, with the underlying structure being weakened and exposed to further damage when the roof is removed.
As a result, many different systems and devices have been developed for securing a roof positively to its underlying structure, and/or to the terrain underlying and/or surrounding the structure. Many such systems incorporate straps or cables, which are anchored to the foundation of the underlying structure, or to the surrounding terrain. Most such systems further incorporate some type of bearing plates or the like, which are placed atop the roof for the cables or straps to bear against in order to avoid damage to the roof covering (shingles, etc.) due to chafing of the cables or straps thereon.
However, a characteristic of such systems is that the cables or straps must be stretched longitudinally over the roof and the bearing plates or the like thereon. The cables or straps generally have on the order of a few hundred pounds of force applied to them, in order to exert a positive downward force upon the underlying roof. This results in a certain amount of longitudinal resistance along the length of the cables or straps, as they drag against their underlying bearing plates. The result of this can be uneven forces applied to the cables or straps, with the frictional drag pulling the bearing plates in a direction along the length of the straps or cables, rather than applying a purely compressive load to the roof structure to hold it in place. Depending upon the specific direction and magnitude of such longitudinal forces along the straps or cables applied to the bearing plates, the forces may be additive to the horizontal wind loads applied to the structure and may weaken the structure further, even though the roof is being held securely in place.
The present invention provides a solution to the above problem by reducing the friction between the tiedown straps used with the present invention, and the underlying bearing plates. Each of the bearing plates includes at least a pair of spaced apart support arms extending therefrom, with the distal ends of each pair of support arms having a roller secured therebetween. The tiedown straps bear against the rollers, which are free to rotate or revolve upon their axles extending across the support arm pair. Thus, practically no longitudinal force is transferred to the underlying base plate resting upon the roof structure. Rather, substantially all of the force developed by the tiedown strap against the underlying bearing plate comprises a compressive force, acting to force the plate directly against the roof structure. This also equalizes the tensile forces along each segment of the tiedown strap, between each of the rollers and between the outermost rollers and the opposed ground anchors.
The present wind cap assembly provides numerous advantages over many other previously developed systems. Using the present system, no modifications are required to the building structure or to its foundation. The tiedown straps never contact the building structure itself; only the bearing plates contact the roof structure. Also, the tiedown straps and bearing plates are easily removed when not needed, and may be quickly reinstalled when needed once the ground anchors have been installed.
A discussion of the related art of which the present inventor is aware, and its differences and distinctions from the present invention, is presented below.
U.S. Pat. No. 777,441 issued on Dec. 13, 1904 to Wily Small, titled “Roof Anchoring Device,” describes a hold-down system comprising a series of cables which extend over the roof of the structure from opposite ground anchors. The Small system requires that the roof be modified with cable passages along the eaves, and the cable guides placed upon the roof structure are permanently secured to the roof by nails or screws. Small provides cable guides in the form of longitudinal channels through which the cables pass, but no means (rollers, etc.) is provided for reducing the friction of the cables as they are stretched across the roof structure and through the guides. Finally, Small also provides a ridge line base plate having an angle therein corresponding to the gable angle of the roof, but Small must provide separate plates for each different gable angle, as his ridge line plates are formed as unitary, monolithic components having fixed gable angles formed therein.
U.S. Pat. No. 1,864,403 issued on Jun. 21, 1932 to Charles B. Bradley, titled “House Anchor,” describes a system more closely related to that of the above noted '441 U.S. patent to Small than to the present invention. The Bradley system comprises a series of eyebolts which are screwed permanently into the roof structure, along with holes formed in the eaves for passage of the cables therethrough. As in the case of the Small roof anchoring system discussed above, Bradley fails to provide any means for reducing the friction of the tiedown lines as they pass through the guides, nor does he provide any means for adjusting the relative positions of the lines and guides.
U.S. Pat. No. 3,309,822 issued on Mar. 21, 1967 to William H. Dunkin, titled “Exterior Anchoring Apparatus For Surface Sheet,” describes a series of tie rods and clamps for securing corrugated or other sheet panels to a roof. The Dunkin system does not anchor the roof to any underlying structure and cannot prevent the entire roof from being blown from the underlying building in a high wind, as can the present invention.
U.S. Pat. No. 3,335,531 issued on Aug. 15, 1967 to Nardie F. Grimelli et al., titled “Tie-Down For House Trailers Or The Like,” describes a series of tiedown embodiments for securing a mobile home to the underlying surface. In one embodiment a flexible cable or chain passes through guide channels placed on the structure, in much the same manner as the ridge and eaves mounted channels of the '441 U.S. patent to Small, discussed further above. Grimelli et al. do not provide any means for reducing friction along the length of the cable or means for guiding such a hold down cable over the ridgeline of a gabled roof, as provided by the present invention.
U.S. Pat. No. 3,828,498 issued on Aug. 13, 1974 to Robert A. Jones, titled “Method Of Stabilizing A Comparatively Flat Roofed Structure Against Wind,” describes the use of adhesive for the permanent attachment of a relatively large number of concrete blocks atop the roof of a mobile home. The blocks merely add weight and break up the airflow over the roof. Jones does not provide any means of positively tying the blocks or the underlying roof structure to the underlying terrain, as provided by the present invention.
U.S. Pat. No. 5,311,708 issued on May 17, 1994 to Filmore O. Frye, titled “Anchor System For Completed Structures,” describes a series of means for securing various components of a building structure to the underlying surface. One embodiment comprises brackets which secure the roof trusses and rafters to the underlying wall stud structure, but not to the underlying terrain. Another embodiment provides for securing the exposed portions of the shingles to the underlying roof sheathing. Yet another embodiment provides for securing the exposed ends of the rafters to the building foundation or to the underlying terrain. None of the embodiments provide tiedown straps or lines which pass over and across the building to secure to opposed ground anchors on opposite sides of the building, nor any low friction guide means for such tiedowns, which features are a part of the present invention.
U.S. Pat. No. 5,319,896 issued on Jun. 14, 1994 to Ronald C. Winger, titled “Apparatus And Method For Securing Building During High Wind Conditions,” describes a series of tiedowns which secure to the exposed ends of the rafters and to ground anchors somewhat spaced from the structure. Winger provides for the retraction of his tiedowns into containers secured to the rafters for storage when not required. No tiedown system passing completely over the roof structure and securing to ground anchors on opposite sides of the building structure is disclosed by Winger. Moreover, Winger has no motivation to provide base plates with rollers atop the roof, as provided in the present invention, as his tiedowns do not pass over the roof structure.
U.S. Pat. No. 5,355,640 issued on Oct. 18, 1994 to Filmore O. Frye, titled “Anchor System For Completed Structures,” is a divisional patent of the '708 U.S. patent of the same title and to the same patentee discussed further above. The same points raised in the discussion of the '708 U.S. patent are seen to apply here as well.
U.S. Pat. No. 5,384,993 issued on Jan. 31, 1995 to Belton R. Phillips, titled “Tie Down For Building Structures,” describes a completely concealed system in which tension rods are secured to brackets holding down the ceiling joists or rafters to the top plates of the walls, with the rods passing through the walls and bottom plates to anchors in the underlying ground. The Phillips anchor system does not pass over the roof, and accordingly does not include any form of base plates and rollers disposed upon the top of the roof for applying force to the roof from overlying tiedown straps.
U.S. Pat. No. 5,388,378 issued on Feb. 14, 1995 to Filmore O. Frye, titled “Anchor System For Completed Structures,” is another divisional patent of the '708 U.S. patent of the same title and to the same patentee discussed further above. The same points raised in the discussion of the '708 U.S. patent are seen to apply here as well.
U.S. Pat. No. 5,448,861 issued on Sep. 12, 1995 to Donald L. Lawson, titled “Method And Apparatus For Securing Parts Of A Building To Each Other And To A Foundation,” describes the installation of tension straps within the walls of a structure. The bottom ends of the straps are anchored to the foundation of the building, with the upper ends of the straps being secured to brackets, which, in turn, secure to the ceiling joists and/or rafters of the structure. The result more closely resembles the assembly disclosed in the '993 U.S. patent to Phillips, discussed further above, than it does the present invention with its exterior tiedown straps.
U.S. Pat. No. 5,491,935 issued on Feb. 20, 1996 to Thomas Coxum, titled “Roof Anchor System,” describes another concealed system in which the tension components are installed within the walls and secure the upper structure to the foundation. The Coxum system thus more closely resembles the assemblies disclosed in the '993 U.S. patent to Phillips and the '861 U.S. patent to Lawson, both discussed further above, than it does the present invention.
U.S. Pat. No. 5,537,786 issued on Jul. 23, 1996 to James P. Lozier et al., titled “Hurricane-Resisting Building Roof Structure Tie-Down,” describes a system having a series of guides which permanently attach to the ridge and eaves of the roof, with corresponding straps passing over the guides and anchored to ground anchors on each side of the structure. The Lozier et al. system differs from the present invention in several respects: (1) no rollers are provided to essentially eliminate friction as the tiedown straps are tightened; (2) no adjustment is provided for different gable angles, in the roof ridge guide; (3) Lozier permanently secures all of his tiedown strap guides to the roof structure; (4) Lozier requires that eaves guides of completely different configuration from the roof ridge guide, be attached beneath the eaves of the structure; (5) Lozier also requires that the rain gutters be modified to provide wells through which the tiedown straps pass, rather than providing eaves guides which carry the straps outwardly over and past the gutters, as in the present system; and (6) Lozier secures the lower ends of the straps to the foundation of the structure, rather than to ground anchors somewhat separated from the structure.
U.S. Pat. No. 5,570,545 issued on Nov. 5, 1996 to James A. Adams, titled “Apparatus For Holding A Roof On A Building During High Winds,” describes a system in which the tiedown straps passing over the roof secure alternately to opposite rafter ends and over the roof to opposite ground anchors. This has the effect of placing the entire roof under a series of shear forces, with each adjacent tiedown applying a force across the roof opposite that of its neighbor tiedown. Adams provides such a system in order to equalize the lateral forces on the walls beneath the roof, but blowdown of the wall structure has never been a problem so long as the roof remains attached to the structure. However, it is important to relieve lateral stresses on the roof structure, which the present invention accomplishes by means of the base plates and their rollers, over which the tiedown straps pass. Adams fails to provide any form of plate or guide between the tiedown straps and the roof itself. The tiedowns rest directly upon the surface of the roof, where they may abrade the shingles and/or otherwise damage the roof if any play between the tiedowns and the roof surface occurs.
U.S. Pat. No. 5,579,794 issued on Dec. 3, 1996 to Joseph Sporta, titled “Apparatus And Method For Securing An Object Against Gale-Force Winds,” describes a large net which is stretched over a mobile home and secured by ground anchors. No guides or other apparatus for preventing direct contact between the net and the underlying structure are disclosed. There would appear to be some problem with entering and exiting the structure with the net in place, as its lower edge appears to be positioned very close to the ground when installed. This is not a problem with the spaced apart tiedown straps used with the present structural tiedown invention.
U.S. Pat. No. 5,623,788 issued on Apr. 29, 1997 to Uwe H. Bimberg et al., titled “Roof Anchoring Apparatus,” describes a system in which a series of cables are passed over a corresponding number of bracket assemblies on the roof, to hold the roof firmly in place. The bracket assemblies differ from the present system in that they must be raised above the underlying structure to provide clearance for a downwardly extending flange. The flange extends downwardly past the eaves when installed at that location, but requires additional structure when installed elsewhere on the roof. The present system uses a series of essentially identical base plates, which may be installed singly or as hinged together pairs across the crest of the roof as required. In any event, Bimberg et al. fail to disclose any form of rollers which serve to reduce or essentially eliminate friction between the straps or cables and the underlying roof plates.
U.S. Pat. No. 5,687,512 issued on Nov. 18, 1997 to Norman W. Spoozak et al., titled “Hurricane Lockdown System,” describes a roof tiedown assembly comprising a cable contained in the eaves of the roof, with a series of cables connecting the eaves cable to a series of ground anchors. No tiedown straps, cables, or lines pass over the upper surface of the roof, as they do in the present invention. Accordingly, Spoozak et al. do not disclose any form of guides and strap rollers for placement atop a roof, as provided by the present invention. Moreover, the Spoozak et al. system requires modification to the roof or installation during construction of the roof, unlike the present invention which is installed over an existing roof structure with no modification to the roof.
U.S. Pat. No. 5,791,090 issued on Aug. 11, 1998 to Harris M. Gitlin et al., titled “Variable Tension Roofing And Structural Protective Harness,” describes the use of an extremely large “shade cloth” stretched over the entire structure and extending to the tiedown anchors installed in the ground surrounding the structure. Gitlin et al. provide rollers along the roof crest, but the cover does not roll back and forth over the rollers as the straps do in the present invention. Rather, the roller is used to roll up the shade cloth material thereon when wind protection is not required. The Gitlin et al. apparatus bears a closer resemblance to the covers disclosed in the '794 U.S. patent to Sporta than it does to the present invention.
U.S. Pat. No. 5,819,477 issued on Oct. 13, 1998 to George Gaffney, titled “Apparatus And Methods For Securing A Building,” describes a system using a series of straps which pass over the roof. The straps pass through a series of gabled plates along the crest of the roof, but the straps are not raised above the roof. In fact, the straps pass through slots in the plates and bear directly against the roof surface at the crest. No other bearing plates are provided by Gaffney. In contrast, the straps of the present invention never come in direct contact with the roof structure, but are separated therefrom by a series of base plates along the span of each strap passing over the roof. Moreover, Gaffney does not disclose any rollers or adjustable roller support in the single type of gable plate he provides.
U.S. Pat. No. 5,983,572 issued on Nov. 16, 1999 to Bernabé Laboy, titled “Roof Tie-Down Support Member,” describes a series of plates for installation on the surface and along the ridgeline of a roof, with the plates having transverse grooves therein for the installation of transverse cables thereacross. Laboy does not provide any cables extending over and across the ridge of the roof, as provided in the present invention. Moreover, no rollers to minimize friction between the cables and the plates and to equalize tensile forces along the cables between plates are provided by Laboy. In addition, Laboy does not secure his roof tiedown system to the ground, but rather to the underlying building structure. In contrast, the present tiedown system utilizes ground anchors for securing the straps.
U.S. Pat. No. 6,088,975 issued on Jul. 18, 2000 to J. Parr Wiegel, titled “Hurricane Protection For Mobile Homes And Small Buildings,” describes a large tarp which is stretched from a ground anchor line on one side of the structure, over the structure to an opposite ground anchor line. Wiegel utilizes a roller having a length equal to that of the tarp, with the roller being installed in the ground or along the eaves of the structure. The tarp is rolled onto the roller for storage. No guide rollers extending from roof plates are provided by Wiegel. The Wiegel apparatus more closely resembles that disclosed in the Gitlin '090 U.S. patent, than it does the present invention.
U.S. Pat. No. 6,161,339 issued on Dec. 19, 2000 to Robert M. Cornett, Sr. et al., titled “Structural Tie-Down Apparatus,” describes another system using tension rods concealed within the wall structure. The lower ends of the rods are anchored in the foundation, while the upper ends are secured to a cable installed across the ends of the rafters. This system does not provide any means of securing the roof sheathing, as no external tiedown apparatus is provided.
U.S. Pat. No. 6,269,593 issued on Aug. 7, 2001 to Thomas Thompson, titled “Roof Tie Down Connecting Fork And Yoke,” describes a system having a pair of hinged together plates permanently secured to the end gable rafter of a roof structure. A bolt serves as the pintle of the hinge, and extends above the roofline for the securing of roof tiedown components thereto. The lower end of the bolt extends downwardly for the attachment of an anchor strap thereto. The problem with this system is that in most new construction, the end gables are constructed in the field, and are nailed to the prefabricated, otherwise flat trusses used to support the roof. Thus, there is no structural continuity extending from the gable eaves overhang to the rest of the roof structure, other than any roof sheathing which may be applied. Moreover, Thompson does not provide any external anchors extending over the central area of the roof. Rather, he relies entirely upon two opposed anchors at each end of the gabled eaves, which do not provide significant anchoring strength, as noted above. No roof mounted base plates or adjustable strap support rollers are disclosed by Thompson.
U.S. Patent Publication No. 2001/37,611 published on Nov. 8, 2001, titled “Anchor For A Structural Tie-Down Apparatus,” is a continuation in part of the issued '339 U.S. Patent, which has already been discussed further above. The same differences noted above between the '339 U.S. patent to Cornett, Sr. et al. and the present invention are seen to apply here, as well.
U.S. Patent Publication No. 2002/100,226 published on Aug. 1, 2002, titled “Truss Anchoring Assembly For Buildings,” describes yet another concealed tiedown installation with tension rods passing through the walls and securing to brackets at the rafter ends. The Huppert assembly is more closely related to the systems disclosed in the Lawson '861, Coxum '935, and Cornett, Sr. et al. '339 U.S. patents, each of which has been discussed further above, than it is to the present invention.
U.S. Patent Publication No. 2002/134,414 published on Sep. 26, 2002, titled “Flexible Wind Abatement System,” describes still another tarp which is installed to completely cover the building structure. The Gower system thus more closely resembles the tarp covers of the Sporta '794, Gitlin et al. '090, and Wiegel '975 U.S. patents, each of which is discussed further above, than it does the present roof anchor invention.
U.S. Patent Publication No. 2002/166,289 published on Nov. 14, 2002, titled “Building Tie Down Kit For Securing Roofs, Doors, And Windows Against Storm Wind Damage And Method Of Assembly,” describes a chain envelope which is secured over the top of a building structure. The result is closer to the various tarps and the like disclosed in the Sporta '794, Gitlin et al. '090, and Wiegel '975 U.S. patents than it is to the present anchoring system invention.
Finally, U.S. Patent Publication No. 2002/189,174 published on Dec. 19, 2002, titled “Retrofit Hurricane And Earthquake Protection,” describes a large number of patterns for forming a series of metal brackets, and the brackets formed therefrom, for use in more securely tying together various building components at the time of construction. No external tiedowns or roof plates are provided by Thompson.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. Thus a wind cap for buildings solving the aforementioned problems is desired.